"I would hope the Federal Trade Commission can help us" by probing the run-up in prices, Reid said in response to a reporter's question about what lawmakers could do to tackle rising retail gasoline prices.

Average U.S. retail gasoline prices are now at nearly $3.72 per gallon, up from $3.37 a year ago. The price could pass $4, especially if political tensions with Iran, a major producer, continue into the U.S. summer driving season that increases demand.

The rapid price hike has brought a barrage of finger-pointing by Republicans in Congress at President Barack Obama, who they blame for blocking some domestic oil production projects.

Democrats meanwhile are calling for a range of actions, including possibly tapping the Strategic Petroleum Reserve to bring more oil into the market and lower prices and encouraging Saudi Arabia to ramp up its production.

Last year, as gasoline prices spiked, the FTC probed whether oil companies had engaged in anticompetitive practices or had manipulated crude oil prices. So far, the agency has not released any findings of wrongdoing.

In 2006, the FTC concluded that companies did not cause an increase in prices four years earlier by restricting refining capacity or cutting petroleum inventories.

Another report from the FTC last September said that crude oil prices were the main contributor to U.S. gasoline prices, downplaying the impact of oil industry consolidation.